Corda 5 Developer Preview release notes

The Corda 5 Developer Preview, released on 28 September 2021, showcases the core features of the upcoming Corda 5.0 release to invite feedback, and give you a chance to experiment with some of the new aspects of future Corda 5 releases.

In this developer preview

Intended for local deployment, experimental development, and testing only, this preview includes:

Changes from Corda 4

Some features available in Corda 4 have been replaced with new functionality. These are:

See the Corda 5 Developer Preview overview for more details.

Known issues

There is a known issue with use of anonymous classes in Java when extending a flow.

When extending a flow, such as SignTransactionFlow you may typically use an anonymous class, like:

SignedTransaction signedTransaction = flowEngine.subFlow(new SignTransactionFlow(counterpartySession) {

    @Override
    protected void checkTransaction(SignedTransaction stx) throws FlowException {

    }
});

However, there is an issue which prevents this from working.

To work around this issue, use static classes in Java when starting subflows that require extending a flow.

For example, in the above case, use:

@Suspendable
@Override
public SignedTransaction call() throws FlowException {
    SignedTransaction signedTransaction = flowEngine.subFlow(new MySignTransactionFlow(counterpartySession));
    return flowEngine.subFlow(new ReceiveFinalityFlow(counterpartySession, signedTransaction.getId()));
}

public static class MySignTransactionFlow extends SignTransactionFlow {

    MySignTransactionFlow(FlowSession counterpartySession) {
        super(counterpartySession);
    }

    @Override
    protected void checkTransaction(@NotNull SignedTransaction stx) {

    }
}

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